Sudoku by MindMagik [iPhone]

Sudoku by MindMagik provides an engaging, realistic 3D puzzle experience from beginner to diabolical.
Choose from over 3600 uniquely solvable puzzles, or add your own. Earn up to 70 different medals for achieving challenges.
An intuitive drag-and-drop interface allows numbers to easily be added, moved, replaced or removed.
With a single tap, zoom in and efficiently add multiple pencil notes across a block. This is great for adding notes in pairs.
Learn solving techniques by using small or big hints. Solving techniques range from basic to advanced with step-by-step explanations.

Features:

* Improve your Sudoku skills by solving puzzles with small hints. Small hints indicate what to look for without directly revealing the next step. Switch to a big hint, if necessary, while learning a particular solving technique.

* Enter a custom puzzle, or add one from a book, paper or magazine. The puzzle difficulty is automatically categorized and is available to play or solve with a step-by-step explanation.

* Over 60 types of hinting algorithms, including Single/Pair/Triple/Quad/Quint types, X-Wings, XY-Wings, XYZ-Wings, seven different categories of Unique Rectangle, Swordfish, Jellyfish, Squirm-bags, Finned and Sashimi fish , and several other advanced chaining techniques.

* Highlight all instances of a number, pencil note or notes, to help identify number placements or note elimination techniques.

* Unlimited undo and redo. Retrace your steps all the way back to the beginning of the game or to a particular point in the game.

* Improve on the time for a previously solved puzzle, or solve again without using hints to earn more stars.

* Save the current position as a bookmark. Return to the saved position at any time. The game is autosaved when switching applications or after an unexpected power failure.

* Interactive tutorial available.